Orally administrable film-, tape-, or sheet-form preparations that are to be disintegrated or dissolved by saliva without being chewed are already available as ten or more over-the-counter drugs (OTC drugs) overseas. In Japan, those preparations are available as several ethical pharmaceuticals.
Such a film-form preparation contains a drug dispersed or dissolved in a film-form base. In an exemplary method of producing thereof, a water-soluble polymer is dissolved in a solvent and a drug is dissolved or dispersed therein, and the resulting dispersion or solution is formed into a film and then dried.
The following patent literatures disclose such film-form preparations. Patent Literature 1 discloses a preparation including a film-form base formed of a tannin substance and hydroxypropyl cellulose or a mixture of hydroxypropyl cellulose and polyvinyl pyrrolidone, and a drug added to the film-form base. Patent Literature 2 discloses a film-form preparation containing a drug, an edible water-soluble film forming agent, and low-substituted hydroxypropyl cellulose. Patent Literature 3 discloses a rapidly dissolving film-form preparation that contains a drug and an edible polymer substance, has a breaking strength and a tensile strength within predetermined ranges, and dissolves within 60 seconds in the mouth. Patent Literature 4 discloses a soluble film that contains an active ingredient having a water solubility of less than about 1 g/4 mL at room temperature and has a water content of less than about 15% by weight.
Though it is not in the film form, Patent Literature 5 discloses a rapidly dissolving preparation that is obtainable by dissolving/dispersing a drug, a saccharide, and polyvinyl pyrrolidone in an organic solvent to prepare a suspension, filling the suspension in a mold for preparations, and removing the organic solvent.
However, many of the film-form preparations having been disclosed up to now contain sugar or sugar alcohol as an excipient for ensuring the film strength. The sugar or sugar alcohol is in the state of being dissolved or recrystallized in the solvent. For this reason, those conventional film-form preparations give a sticky feeling attributed to the water-soluble polymer in the mouth. Moreover, the sticky feeling when handled with the fingers is also a problem.
To solve such problems, Patent Literature 6 discloses a method of improving the disintegration property of an oral film-form base and an oral film-form preparation in the mouth while preventing dissolution or recrystallization of sugar or sugar alcohol by dispersing particles of the sugar or sugar alcohol in the film containing an edible polymer. Further, various studies are also made on the size of particles added to film-form preparations (see Patent Literatures 7 to 9).